Alessandro Nesta says Roma stalwart Francesco Totti has been able to play at such a high level into his forties due to his "extraordinary capabilities".
Totti is a legend at Stadio Olimpico having spent his entire career with Roma, winning Serie A once and the Coppa Italia twice with the club.
The former Italy international, a World Cup winner with the Azzurri, is also Roma's all-time leading goalscorer and recently suggested he could continue his playing career next season despite previous suggestions this would be his last.
Nesta starred for Roma's city rivals Lazio during his playing career, but spoke of his admiration for his ex-Italy team-mate.
"He [Totti] is my age. I am here coaching [at Miami FC], he is there playing," Nesta told Omnisport.
"Still playing well, not only playing. He is special and equipped with extraordinary capabilities that at 40 let him have fun and make the others have fun."
Roma face off against Lazio in the first derby of the campaign on Sunday.
Nesta also has experience of playing in the Milan derby for AC Milan, and says both fixtures hold a special place in his heart.
"Both are very important," he added. "I played 10 years in one place and 10 years in the other.
"Lazio was the club in my heart, I grew up there but Milan then let me win."